City officials are calling on New Yorkers to get vaccinated against the measles after an outbreak of the highly contagious viral infection in northern Manhattan and the Bronx.

The Department of Health said Friday that it had identified 16 cases of measles since February. Nine cases involve children. The department said there were four hospitalizations in this latest outbreak. Some of the children had not been vaccinated against the virus and the adults, while assuming they had been vaccinated, could not provide documentation.

Cases were identified in the Manhattan neighborhoods of Inwood and Washington Heights, as well as in southwestern sections of the Bronx.

Measles is characterized by a combination of rash, high fever, cough, red eyes and runny nose. Complications can include pneumonia, miscarriage, brain inflammation and even death.

Vaccination can begin at 12 months of age. New Yorkers can call 311 for vaccination providers.

While measles was largely eradicated in recent years in the U.S., travelers who visit or come from countries where the disease is still a major public health crisis have reintroduced it. A backlash in the U.S. against vaccination has left many youngsters and adults vulnerable to infection.

The Centers for Disease Control reported that there were 159 confirmed cases of measles in the U.S. between January and August 2013, the latest numbers available on the agency's website.